Autism spectrum disorder is a neurodevelopmental condition characterized by a heterogeneous grouping of social-communication impairments and behavioral phenomena that are observed in early development and often accompanied by an array of co-occurring issues. The prevalence of autism spectrum disorder (ASD) has risen markedly in the last several years (1 in 68 per a 2014 CDC estimate), and the evidence base for early intervention and other treatment strategies supports the idea that a timely and appropriate diagnosis is critical for promoting positive outcomes for children and their families.
With ASD, there can be wide variety in a young child’s presenting symptoms. Although some youth clearly manifest the hallmark features of ASD, ever-changing development, complicated cognitive profiles, family difficulties, co-occurring mental health problems, and evolving nosology (such as DSM changes) can contribute to the difficulty providers encounter in fully interpreting and identifying ASD symptoms in the course of a typical primary care visit. This case example outlines assessment and diagnostic strategies that may help pediatricians to better understand the complexities of diagnosis, assessment, and treatment for children suspected of having ASD. Ideally, a diagnostic evaluation would quickly follow a standardized screening tool that is positive for concern for ASD (such as the Modified Checklist for Autism in Toddlers – Revised) between the ages of 18 and 24 months.
Everett is a 4-year-old boy who presents to an autism diagnostic clinic after his parents expressed concerns about his behavior. Everett is described to be a rigid, stubborn, strong-willed, and easily frustrated boy who began to exhibit aggressive behaviors at 18 months of age. He continues to have almost daily temper tantrums. Notably, Everett did not begin to use single words with communicative intent until he was 24 months old. He will often repeat words nonfunctionally and utter nonsensical verbalizations while spinning in circles and rocking back and forth. Everett enjoys being around peers but has difficulties engaging appropriately with other children, exhibiting poor physical boundaries. Everett’s hearing and vision were previously tested to be without deficit, and there is no history of seizure activity or indication of an underlying metabolic disorder.
Everett presents with some signs and symptoms to suggest ASD (namely his communication and language impairments accompanied by some atypical social relatedness and repetitive behaviors). His presentation, however, has many characteristics that while common to ASD are not entirely specific to the diagnosis in a preschooler, and could occur with other disorders. For example, Everett’s social difficulties could be the result of an emerging behavioral disorder (an oppositional defiant disorder) or a primary expressive language disorder, which may manifest with frustration intolerance due to communication difficulties.
With children like Everett, a comprehensive autism diagnostic assessment should be obtained and preferably be comprised of a minimum of two components – a caregiver interview and an observational assessment ideally conducted by an experienced clinical interdisciplinary team. Additionally, evaluations of adaptive skills, cognitive profile, family functioning, social-emotional/behavioral functioning, and sensory issues can be useful to inform treatment planning and diagnosis. Ultimately, the diagnosis of ASD is made after clinicians integrate available information and fully consider the range of differential diagnoses. Clinicians who may participate in the diagnostic process include developmental pediatricians, child psychiatrists, clinical psychologists, speech-language pathologists, and other allied health professionals.
Clinical guidelines suggest that gathering a thorough developmental history, assessing for the characteristic impairments that support an ASD diagnosis, and establishing current levels of functioning can be performed using the semistructured Autism Diagnostic Interview – Revised (ADI-R) with primary caregivers. Information about a child’s social interactions also can be obtained with the use of the Social Responsiveness Scale (SRS), which can yield multi-informant data that helps to capture a youth’s functioning and peer interactions in different settings, including home and school.
The observational assessment ideally utilizes the Autism Diagnostic Observation Schedule (ADOS), a standardized instrument that can evaluate domains of reciprocal social interaction, communication, restricted interests, and repetitive behaviors in a developmentally informed manner. Clinicians should be mindful that certain behaviors may not be displayed during the diagnostic evaluation, and as such, scoring on the ADOS should be integrated with other sources of information and interpreted within a developmental framework; no single result on one instrument is sufficient to make or break an autism diagnosis.
The above-mentioned tools were used in Everett’s assessment. Appraising the collected data, his scoring on the ADOS suggested an autism diagnosis, but information from the ADI-R and SRS were not conclusive. To further evaluate Everett, we incorporated a broad developmental evaluation tool, the Mullen Scales of Early Learning, which provided us with a lens through which to interpret his profile of impairments and strengths. Everett scored with average to above-average skills across all domains, which helped us conceptualize that his social, language, and behavioral struggles were not the result of a global developmental delay or intellectual disability.